How to scale multiple objects in Blender 2.82+ without a plugin
Change the scaling mode from 'Median point' to 'individual origins'.
Scaling three spheres 3 increments on the x axis with the default - 'median point'.

Scaling three spheres 3 increments with transform settings set to individual origins.

What this does is allow the objects simultaneously selected to scale around their own origins instead of the active selected object. (The one highlighted in yellow).
To scale the objects &quot;42%&quot;, go to select mode (the default when you open blender), select all of the objects, make sure you have the transform mode set to individual origins, and press S then press X. Type in '.420' to set the scale to 42%. You do not need to be in transform or scaling mode in object mode to scale an object.